An Improved Grid Connected PV Generation Inverter Control System and Analysis of %THD for Inverter

In this paper we study the operational principle and the structure of the grid-connected photovoltaic system inverter control system and analysis of % THD for inverter with filter and without filter.Mainly the two inverter control methods.1) voltage source inverter control method 2) power type PWM inverter control method.On the basis of above two kinds of inverter control methods, we will present an improved PWM inverter control system that can be applied in grid-connected PV generation and uses MATLAB/Simulink software to simulate and analyze.The result of the simulation shows that the improved inverter control system can effectively control the grid current waveform which tends to sine wave, means while it can achieve the maximum power point tracking, besides it is able to put the arbitrary power out to the load or to the grid, while the control system has a good stability.It also shows that as the increasing number of inductive load penetrate the grid, the load waveform distortion is produced, but it will not affect the reliability of power supply.In this paper, we study also the different types of inverter were designed by using MATLAB / SIMULINK and %THD (Total harmonics distortion) was compared. I.